Rectifier Quest

[IEaudiodude]

I ave an Olchen EL34-B amplifier, My Psvane 5U4G Rectifier tube started to arc, I have a New Sovtek 5AR4 sitting here I would like to use instead of purchasing another tube. AI says it should be fine, but I don't trust AI all that much, plate voltage will increase a bit .Does anyone here have one of these amps or do you know if it is okay to substitute the Sovtek for the Psvane ?

 

[mhardy6647]

Is it designed for a 5U4?
Use a 5U4.
Get a good old US 5U4, new or used, you'll be all set. If you're in the US, I'll mail you (a good used) one if you are willing to PM me a mailing address.
The 5AR4 will indeed have less voltage drop -- askin' for trouble.
Not sure any of the current 5AR4 are very good, even when used in a circuit intended for them. Most seem to have lives that are nasty, brutish, and short.

Here's (almost) all you need to know about most vacuum tube HV rectifiers' characteristics. There's a whole (small) "section" on 5U4 "substitutions".

http://www.fourwater.com/files/fullrect.txt

 

[mhardy6647]

From the above.

 

[JeffS7444]

Not sure any of the current 5AR4 are very good, even when used in a circuit intended for them. Most seem to have lives that are nasty, brutish, and short.

I consider the occasional flashes of light from aging Sovtek 5AR4s a form of entertainment included at no extra charge, but those who desire less entertainment might want to consider solid state replacements.

 

[mhardy6647]

Sure... as long as those replacements are designed with appropriate voltage drop and (ideally) a "soft-start" feature.

I'd still be leery of dropping a 5AR4 (GZ34), or an ss replacement module, into the HV supply for that amplifier unless "we" are (i.e., the end-user is) absolutely sure that the amplifier will be OK with the new operating voltages it'll be exposed to. I doubt (?!) that the P/S in the amp is regulated.